An ultrasonic transducer according to the present invention includes: a piezoelectric body 4 to set up ultrasonic vibrations; an acoustic matching layer 3 made of a material with a density of 50 kg/m.sup.3 to 1,000 kg/m.sup.3 and an acoustic impedance of 2.5.times.10.sup.3 kg/m.sup.2/s to 1.0.times.10.sup.6 kg/m.sup.2/s; a lower acoustic matching layer 9 provided between the piezoelectric body 4 and the acoustic matching layer 3; and a structure supporting member 6 that supports the lower acoust...

An ultrasonic transducer in which internal electrodes and piezoelectric elements are alternately layered includes outer electrodes, each being connected to the corresponding internal electrodes. The ultrasonic transducer has a first layered part, a second layered part, a first outer-electrode group, and a second outer-electrode group. The first layered part includes at least the internal electrodes, each being divided in half in a second direction orthogonal to a layering direction, which is a f...

An ultrasonic tool, for bonding two materials to each other by joining a face of one of the materials to a face of the other material using the action of ultrasonic waves applied to one of the materials through another face of the one of the materials, wherein the ultrasonic tool has a coating layer comprising chromium oxide as a main component formed on at least the surface of the tool that is in contact with the face of the one of the materials through which the ultrasonic waves are applied to...

Method and apparatus for measuring the difference in length between two paths through sound transmitting medium. In one embodiment, a U-tube manometer has transducers placed near the bottoms of the columns of liquid in the two manometer legs. An electronic circuit causes the transducers to emit simultaneous sound signals directed toward the tops of the columns. A counter accumulates a count of the pulses produced by a high frequency oscillator between the time the echo of the sound signal in the...

The present invention provides an ultrasonic transducer having uniform characteristics. Because the characteristics of a pair of ultrasonic transducer are equalized with each other, measuring accuracy of an ultrasonic flowmeter can be improved. Electrical connection from an electrode surface 13 of a piezoelectric body 11 to an external electrode is achieved not by soldering but by an electroconductive elastic body 16. As a result, variations of the frequency characteristics due to thermal load o...

Method and apparatus for measuring the difference in length between two paths through sound-transmitting medium. In one embodiment, a U-tube manometer has transducers placed near the bottoms of the columns of liquid in the two manometer legs. An electronic circuit causes the transducers to emit simultaneous sound signals directed toward the tops of the columns. A counter accumulates a count of the pulses produced by a high-frequency oscillator between the time the echo of the sound signal in the...

A low power ultrasonic flowmeter to be powered by a two wire power supply loop is described, comprising: an ultrasonic flow sensor, a signal processing unit for determining a measurement result based on measurements performed by the ultrasonic flow sensor, an input/output unit to be connected to the two wire loop, for controlling a current of the power supplied to represent the measurement result, for receiving power from the power supply loop, and a power management system, for an energy effici...

There are provided an ultrasonic transducer that performs transmission and/or reception of an ultrasonic wave, and a propagation medium portion that forms a propagation path of the ultrasonic wave. A density and an acoustic velocity of the propagation medium portion, and a density and a sound velocity of a fluid that fills a circumjacent space are appropriately set, and a propagation loss of the ultrasonic wave into the fluid is reduced to almost zero by refracting the ultrasonic wave at an appr...

The invention is constructed such that, in an ultrasonic probe in which a peripheral side face of a piezoelectric plate is covered with a shielding case, and an acoustic matching layer is provided on an ultrasonic wave transmission reception face including the piezoelectric plate and the shielding case, there is provided a voltage proof material on a tip side of the shielding case including at least an aperture end face. Moreover, the piezoelectric plate may be a divided type ultrasonic probe wh...

An ultrasonic transducer having an effective center frequency of about 42 MHz; a bandwidth of greater than 85% at 6 dB; a spherical focus of at least 0.5 inches in water; an F4 lens; a resolution sufficient to be able to detect and separate a 0.005 inch flat-bottomed hole at 0.005 inches below surface; and a beam size of approximately 0.006 0.008 inches measured off a 11/2 mm ball in water at the transducer's focal point.